[PATCH] D46527: Object: Find terminator correctly when getting long filenames from GNU archives

[Hans Wennborg via Phabricator via llvm-commits]

hans created this revision.
hans added reviewers: inglorion, ruiu.

The code was previously assuming relying on there being a null terminator somewhere in (or after) the string table, something made less likely by r330786.

(Suggestions for how to test this welcome.)


https://reviews.llvm.org/D46527

Files:
  lib/Object/Archive.cpp


Index: lib/Object/Archive.cpp
===================================================================
--- lib/Object/Archive.cpp
+++ lib/Object/Archive.cpp
@@ -175,15 +175,19 @@
                             "the end of the string table for archive member "
                             "header at offset " + Twine(ArchiveOffset));
     }
-    const char *addr = Parent->getStringTable().begin() + StringOffset;
 
     // GNU long file names end with a "/\n".
     if (Parent->kind() == Archive::K_GNU ||
         Parent->kind() == Archive::K_GNU64) {
-      StringRef::size_type End = StringRef(addr).find('\n');
-      return StringRef(addr, End - 1);
+      size_t End = Parent->getStringTable().find('\xa', /*From=*/StringOffset);
+      if (End == StringRef::npos || End < 1 ||
+          Parent->getStringTable()[End - 1] != '/') {
+        return malformedError("string table at long name offset " +
+                              Twine(StringOffset) + "not terminated");
+      }
+      return Parent->getStringTable().slice(StringOffset, End - 1);
     }
-    return addr;
+    return Parent->getStringTable().begin() + StringOffset;
   }
 
   if (Name.startswith("#1/")) {


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